Oxygen apparatus



April 15, 1924. 1,490,641

B. A. SMITH ET AL OXYGEN APPARATUS A Filed Feb. l5 1919 The/'r M Patented Apr.' 1,5, 192,4.

UNITED STATES- BENJAMIN a SMITH, oF Laxnwoon, oiiio, Nn WILLIAM 'Y PENNSYLVANIA. v

Par.um OFFICE.

OXYGEN APPARATUS.

Application led February 15, 1919. Serial No. 277,337.

To all whom t may cof/wem I y Be it known that we, BENJAMIN A. SMITH and WILLIAM G. KEAT, both' citizens of the Unit-ed States, residing at Lakewood, Ohio,

and Pen Argyl, Pennsylvania, respectively,

have invented certain new and'useful Im-v provements in Oxygen Apparatus, of which the following is a speciication. Y

This invention relates to apparatus for supplying oxygen to aviators and others in locations where oxygen is insuiiicient. For

instance, the apparatus of this invention' y may be used to provide oxygen to aviators at great altitudes.4 The apparatus may also be used to provide oxygen to persons who are in atmospheres which are deficient. in oxygen by reason of foulness of the' air, or the presence of noxious gases.

a More particularly, he invention relates to a pressure reducing mechanism for use in connection with such apparatus.'

. It is well known that various forms of apy paratus have been-used for airplane service which were automatic in their operation so far as variations in pressure due to altitude and consequent variations'in the amount of oxygen per cubic foot of air were present. All of these orms of apparatus before known have been open to veryk serious ob jections that temperature changes markedly aected vthe pressure reducing mechanism commonly used to step down the oxygen pressure' from a high storage pressure to a breathable pressure. due to the fact that the forms used were not thermostatically neutral. It, is alsov well known that the temperaturelat a given time` at the earths'surface is muchgreater than the temperature atthe same time ,several thousand feet above the po1nt chosen^on the earths surface as a datum point for the Fig. 1.

Fig. 1.

This defect has beenv that it is, sometimes oxy en. uthermore, it is necessary n to varyt e amount of oxygen so providedin accordance withl the rarefaction of the air. y y A second object of the; invention is'to provide an improved form of valve for conexiiA'r, or PEN ARGYL,

trolling the supply of oxygen so that one or 'y Inore persons` may be supplied with vthe* proper quantity vofv oxygen In anl improved manner at various 1 altitudes;

With the above' and other objects view l tion consistsl in general of certain novel details of construction and combination and as will hereinafter be apparent, the invenarrangement of parts hereinafter fully described and -illustrated in the accompanying drawings and specifically claimed. t

In the' accompanying drawings in which Ilike vcharacters of reference indicate like parts in the several views, V

Fig. 1 is a front elevation of the device as it appearsy on the instrument board of an airplane.

Fig. 2. is a bottom plan thereof. Fig. 3 is a section on the Fig. 4 is a section on -the line 4.--4 of Fig. 5 is anenlarged detail section through the flow indicator.

Fig. 6 is a section on the line/"6--6 ofl Fig. 4. v f v Fig. 7 is a section on thevline 7--7 of Fig. 4. i Fig. 8 is a broken plan View of Fig. 1.` In carrying out the objects of this invention there is provided a base 10 on which the various parts of the apparatus are assembled. Considering now the pressure reduc1n apparatus: On this base 10 there Is secure `a suitableV casing l11, which is held in osi-v tionen the casing bythe screw 12 and ooknut 13. In the base 10 is an opening 14, through which extends a threaded nib 15,

lhaving a screw slot 16 inits lower end. Ther upper or inner end of this nib 15 issecurely soldered or otherwise fastened to the lower side of a corrugated aneroid shell 17 between which and the bottom ofthe casing 11 isa washer 18. On the lower end of the nib 15 is a nut 19 forinin a loclniut. Now; from the foregoing, it wil be seen .that when the nut 19 is rotated so as to compressthe washer 18 between the shell 17 and the lower linek 3-3 of side of the casing 11, an air-tight joint is fformed. Within the'casi-ng 11 is located a U-shaped -yokev20 between the arms of which being loosened for this purpose.

extends a in 21 whereon is pivoted the angular portion of a bell crank lever 22. One arm of this bell crank 22 extends over the aneroid shell 17, and on a vpin 23 carried by this arm 'is pivoted a threaded sleeve 2.4. vScrewed into the threaded sleeve 24 is a mb 25 whichv is coaxial with thel nib 15 and which is likewise fixed securely to the aner-- oid shell 17. Usual springs17 are located in the box 17. Now, it will be observed, that the position of the aneroid shell relative to the overlianging arm of the bell crank lever may be moved atwill to suit the varyingconditions by rotatingthe shell and nibs through the instrumentality of a screwdriver engaging the slot 16, the locknutv 19 The reason of the desirability of this adjustment will presently appear.

Extending.v laterally from the casing v11 is a boss 26 wherein is mounted a sleeve 27 having a minutevopening 28 thereinwhich terminates in` a valve seat 29. Th1s valve bakelite or analogous material carried by the f bell crank lever 22 on the arm thereof which extends over the valve seat. AJvalve seat of bakelite. is found to be particularly satisfactory, for two reasons it is not corroded 'by the oxygen, yand it is slightly softer than 'the' valveseat 29, whereby any lirregularities in the valve seat will indent the bakelite to give a tight seal. vFixed to the basel() by means of the screws 31 is a'boss 32 which is threaded exteriorly to receive the `connections from a high pressure'tank containing oxy en, the tank notbeing here shown. In the oss 26 is formed a seat 33 wherein extends the outer end'of the boss 26, ya compression washer .34 being held between said l outer end and the valve seat 29, the valve seat 291beingheld securely in position by means of solder or the like. Through the boss 32 extends Va passage 35 which, commu- .nicates with the passage `36 terminating in an.v offset portion 37 communicating withl the -opening 28 in the valve(` seat 29. y An extremely important feature of the invention resides in the fact that the aneroid shell 17 has the air normally contained therein exhausted so that the interior pressure is f 'about one millimeterI of` mercury, although this-pressure may vvary in `accordance with 'the conditions obtained in the remainder of the apparatus.

Now `upon the openingof this part of the l device oxygen will be admittedthrough pas- 4Sage 36 and by reason of the pressure vobv tained,lthe valve 30 will open and in consequence will build up' within the casing 11 a Lpressure vwhich will operate to compress) the sides of the' aneroid shell v17 and move them toward -each other.` flhis in turn will rock oxygen passes through the tube 38, the pres-- sure within the casing falls, the'aneroid shell `17 expands, andthe valve'30 is again moved away from its seat to lallow. further oxygen to enter the casing 11. The inrushing gas again shuts the valve 30 and as this operationv is repeated so long as oxygen is passing through the tube 38 the pressure is kept down to the required degree. During this operation the valve canl be heard opening andy closing similarly `to the ticking of a `watch, only much .more rapidly. In other words, the valveactionis intermittent.

I nowl becomes'apparent that the pressure within the casing 11 can be-varied at will by adjustment ofthe nib 25 in the sleeve 24 and v.that by Isuch adjustment the differences in pressure necessary to open and close the inlet valve may bel regulated to suit the prevalent conditions.

In the ordinary form of the device .employing an aneroid shell the aneroid shell is not exhausted and whilethe device set for a given temperature may function properly runder varying conditions of pressure, yet a variation in the temperature -will affect the contents of the shell so that when the temperature rises a greater npressure within the casing l1 before the valve'30 closes and, when the temperaturel` falls, the pressure within the shell decreases thus decreasingthe pressure necessary in the casingl'l to close the valve. supposing the device is used in connection withl anairplane and that it is so adjusted as to operate 'at 'the temperature o f the air near lthe 'earths surface. As the airplane ascends both the temperature and the pressure ofthe air decrease so that the pensates the ltemperature effect ofthe metal of the shell'and therconsequence is that the device is thermostatically neutral.

For the purpose of observing the pressure within the passage 36-the boss 32 is provided with a lug l39 having a suitable 'o enx ing therethrough which communicates wlth a Bourdontube 40mounted within a casing 41 and .operating the usual pointer 42 traversi pression joint 48.

ingA a scale 42, thus constituting a pressure guage.

Consideringnow-the distributing valve for the oxygen which leaves the pressure reducing mechanism heretofore described.- Mounted on the basel() by. means of screws 43 is a cylindrical casing- -14 within which is mounted a rotary sleeve 45 wherethrough extends a plurality of slots 46. The slots 46 communicate with tapered circumferential slots 46.

In the casing 44 is screwed a head 47 whereto the pipe 38 from the pressure reducing device is connected by a suitable com- The other end of the casing 44 is closed by acombined sleeve and cover 49 which holds the valve sleeve 45 in lplace and is provided with an outwardly extending' hollow boss 5() wherethrough passes a stem 51 having pivoted on its inner end a cross bar 52, the ends whereof tit. in slots in one end of the sleeve 45. By

means of this arrangement any eccentricityof the stem'51 relative to the sleeve Valve 45 is compensated.

Fixed on the outer end of the stem 51 is a rock arm 54 to which is connected an adjusting screw 55 slotted at its end. Between the ends of the slotted ends of the screw 55 is pivoted a stem 56 which is connected to one of a series of aneroid cells 57, the other end of the series being fixed to a support 58 by means of a threaded stem 59 provided with adjustingA nuts 60. The threaded stem 59 permits adjustment of the sleeve 45 so that the valve openings 46 may be set as desired.

The remaining cylindrical portion of the casing 44 is closed at one end by a head 62 to which is soldered a tube 63 forming the efflux tube from this portionof the apparatus. To afford communication' between the interior of the sleeve 45 and the interior of the portion of the casing 44 co1n1nunicating with the tube 63, this being preferably termed the chamber 6-1, there is provided a pair of ports 65 and 66. Rotatably mounted within the chamber 64 is a cylindrical valve 67 preferably slightly tapered in form -to form a plug valve. This vvalve 67 has a centrally transposed opening 68 wherewith colnmunicate laterally extended openings 69 arranged preferably at an angle of 180o to each other. The openings 69 may be brought into register with respective ports 65 and 66 by rotating of the valve 67 manually:

In order to hold this valve in position,l

there is provided a closing plug 70 between which and thevalve is located a compressor spring 71, the stem 72 of the valve extending outward as shown. Connected to the stem 72 in such manner as to effect rotation thereof, is a tube 73 carrying on its end a finger operated pointer 74 whereby the valve 67 may be rotated at will so that either port 65 or 66 may be opened or both be closed.

It. is necessary that the user of the apparatus be at all times informed whether the oxygen is flowing properly through the device or not. and to this end there in provided a casing 75 having extended there- 'from a pipe connection '76. nection is for the purpose of receiving one end of the tube whereby the device may be connected to the usual aviatorsmask. The pipe 68 connnunicates withv this casing and en the interior of the casing is an arcuate This pipe con-- painted black or may be processed to form a black surface and on this disc is a spiral line 84 of luminous paint, so that rotation of the disc 83 is visually indicated both day and' night. The casing 75.is preferably covered by a suitable glass 85, with a bezel connection 86 to the casing.

The operation is as follows: High pressure oxygen enters the passage 36, travels through the small passage 28 to the interior of the casingI 11 to till it with oxygen and to increase the pressure there until the valve 3() closes. From the casing 11. the oxygen passes, by pipe 38. to the distributing-valve 44, tending to lower the pressure in the cas` ing. As soon as the pressure falls below a certain point, the aneroid will open the valve 3() to let in more oxygen, so vthat a substantially constant pressure of oxygen will he maintained in the casing 11.

The oxygen passes into the pipe 38 and thence to the distributing valve shown in Fig. 4. From the. interior of the sleeve 45 the oxygen passes through one of the ports 46- and its associated tapered slot 46. The oxygen passes through port v46, intoV the tapered slot 46 and travels along this slot until it reaches thel point where one of the ports 65 or 66 opens into slot 46. After passing through port 65 or 66, the oxygen passes into onel of the passages 69 and thence into pipe 63, then through pipe 63 to the flow indicator 75` where it causes rotation of the fan 82 and disk 83; the oxygen then 4.6 is to adapt the apparatus for delivering oxygen to one. or tivo,A aviators'. Additional slots could. ot course. be provided, to supply suilieient oxygen to any desired number of possible cross-sections` as long as they de` crease gradually in cross-sectional area. The cross-sectional area of the slot for two aviators will obviously be somewhat larger than the slot intended for use with one aviator.

It should bel understood that the Several features of our invention are capable of being carried out in other Ways andthat accordingly the invention be not limited to the precise embodiments here shown by Way of illustration.

1.- A pressure? responsive element of the ane'roid type comprising a shell from which the air has been exhausted to such a dev gree as to render the elementA substantially independent of temperature changes within the shell.

2. A pressure responsive element of the aneroid type embodying a shell ,from which the air has been exhausted to such a degree that changes in conformation of the material ot the. shell due to expansion and contraction are rendered substantially independent ot temperature changes outside of the shell.

3. A pressure responsive element of the i aneroid type, comprising a shell exhausted to such a partial vacuum, that changes in the material of the shell due to expansion and contraction are rendered substantially independent of temperature chan es outside of the shell so that a substantial y thermo'- statically neutral combination is obtained.

In testimony whereof We have afiixed our signatures. l

BENJAMIN A. SMITH; WILLIAM G. KEAT. 

